Where to add Fuel Pump or Primer Bulb - Yanmar 3TN****

[leonz]

If you want an engine service and repair manual contact Foley Engine Service and they will sell you a
Yanmar manual for the Specific engine in your mower.

The diaphram is part and parcel of the engine and the diaphram seal must be maintained.

I would love to see the fuel flow diagram for you engine as it is much more complicated than
a Duetz indirect injection engine fuel system for what ever reason.

 

[coachlarry]

The return line from the injectors discharged in to the fuel tank. Normally the rubber hose connected to a steel pipe so the returning fuel went to the bottom of the tank.
Over time, this return steel pipe would break off. The returning fuel went into the tank. There were no leaks, what is the big deal?
The tractor became hard to start. Air in the system. Bleed the air and all was good until the tractor was shut down for a day or more and then the air problem again.

The steel return pipe which discharged near the bottom of the tank kept air from getting into the fuel lines as it was always below the fuel level. As soon as the pipe broke off air was getting in to the fuel lines as the engine cooled down. Air would rise up into the filters and then sucked down to the injection pump.

If this WSM would help you pm me and I can find a way to make it available.
4100 Compact Utility Tractors


Dave M7040

Put a bulb on yesterday, and priming I heard the return dripping into the tank.... dripping like rain drops! Sonofagun if my return tube isn't there either! On a side note, I tried bypassing the mechanical lift pump and it wouldn't run. So I assume that pump is working properly.